Akademik Veri Yönetim Sistemi
International Civil Engineering and Architecture Conference 2019 (ICEARC’xx19, Trabzon, Türkiye, 17 - 20 Nisan 2019, cilt.1, ss.2173-2180
During the service life of concrete
structures, internal and external effects and micro-cracks occur in the
structure. These cracks cause leakage of harmful substances into the concrete,
deterioration of the strength and durability properties of the concrete,
structural damages and crashes, and the high cost of maintenance and repair of
the concrete structure. It is known that water-dissolved CO2 reacts
with Ca+2 ions in the concrete and can repair the concrete by
forming CaCO3 (limestone) crystals with very little water
solubility. However, for this type of self-repair to occur, there must be water
in the environment and this repair can only be made if the cracks are too
small. Recently, bacterial concrete methods which has ability to self-healing
are used to overcome maintenance and repair costs. In 1994, the first study on
the ability to self-healing with the extra materials that were added to the
concrete during the production of concrete was published by Carolyn Dry of
Illinois University. Eric Schlagen and Henk Jonkers who have been researching
about self-healing concrete by adding bacterial spores and calcium lactate foods
to the mixture while producing concrete have made a remarkable study in this
field since 2006. Bacterial concrete, Bacillus bacterial spores in the medium
of the water-activated nutrients and calcium sources in the range of
appropriate pH values in the concrete due to the formation of a fibrous
structure is caused by precipitation of calcite. Thus, with the precipitation
of calcite, the bacteria are embedded in concrete and the concrete is provided
to improve itself.
In previous studies, it has been shown
that the cracks and voids in the concrete are filled with the ethrengeite and
C-S-H structure when the control and bio-based concrete samples examined by SEM
and XRD are compared. In previous studies, it was observed that mechanical
strength and durability of the concrete is increased. It should be noted that
the concentration of bacteria used in the solution and the ambient pH value is
specified. Although conventional maintenance and repair methods are fast reacting,
and short-term efficient, bacterial concrete method is sustainable, slow and
long-term efficient. In addition, it is an environmentally friendly method
compared to chemical repair methods and is expected to be among the remarkable
materials of the future. The high initial cost leads to a reduction in producer
demand, and the development process must continue to achieve the desired
results and cost. As a result, it will be possible to obtain more durable
structures by not wasting time, saving money and reducing the costs of high
maintenance and repair. In other respects, it is a great advantage for
sustainable development. Technical studies are continuing due to the high cost
and laboratory test results of the bacterial family, as well as the impacts on
the survival of the bacterial family. In this study, previous studies were evaluated,
and some suggestions were made based on these studies.